Baillet, L.

Bièvre, G.

Colombero, C.

Fiolleau, S.

Jongmans, D.

Larose, E.

Valentin, J.

English

Colombero C.

Jongmans D.

Fiolleau S.

Valentin J.

Baillet L.

Larose E.

Bièvre G.

PORTO@iris (Publications Open Repository TOrino - Politecnico di Torino)

04 August 2020POLITECNICO DI TORINORepository ISTITUZIONALESeismic noise parameters as indicators of reversible modifications in slope stability: a review / Colombero, C.;Jongmans, D.; Fiolleau, S.; Valentin, J.; Baillet, L.; Larose, E.; Bièvre, G.. - In: GEOPHYSICAL RESEARCHABSTRACTS. - ISSN 1607-7962. - 21(2019), p. EGU2019-2095. ((Intervento presentato al convegno EGU GeneralAssembly 2019 tenutosi a Vienna (Austria) nel 7-12 April 2019.OriginalSeismic noise parameters as indicators of reversible modifications in slope stability: a reviewPublisher:PublishedDOI:Terms of use:openAccessPublisher copyright(Article begins on next page)This article is made available under terms and conditions as specified in the  corresponding bibliographic description inthe repositoryAvailability:This version is available at: 11583/2746472 since: 2019-08-06T19:13:59ZEGUGeophysical Research AbstractsVol. 21, EGU2019-2095, 2019EGU General Assembly 2019© Author(s) 2018. CC Attribution 4.0 license.Seismic noise parameters as indicators of reversible modifications in slopestability: a reviewChiara Colombero (1), Denis Jongmans (2,3), Sylvain Fiolleau (2,3), Johann Valentin (2,3), Laurent Baillet (2),Eric Larose (2,3), Grégory Bièvre (2,3)(1) Politecnico di Torino, Dept. of Environment, Land and Infrastructure Engineering, Italy (chiara.colombero@polito.it), (2)Université Grenoble Alpes, Université Savoie Mont Blanc, ISTerre, Grenoble, France, (3) CNRS, IRD, IFSTTAR, ISTerre,Grenoble, FranceIn the last decade, there has been a growing application of long-term ambient seismic noise monitoring systemsto landslides and potentially unstable rock sites. Through noise spectral analysis and cross-correlation techniques,these studies were primarily devoted to the identification of an irreversible drop in the detected resonancefrequency (f0) values and/or negative velocity changes (dV/V) uncorrelated with external meteorological factors.Both f0 and dV/V are indeed easy-to-monitor seismic parameters whose irrecoverable modifications may be readas precursors to failure and therefore be used for monitoring and early-warning purposes. Despite the increasingnumber of studies, only in a few monitored cases slope failure was approached and irreversible modifications in f0and dV/V were recorded. By contrast, all the monitored sites showed clear reversible fluctuations in these seismicparameters over time, driven by modifications of the external meteorological conditions. In particular, temperaturewas found to be the main controlling factor on rock sites, while influence of rainfalls and water seepage within theunstable bodies was found to be more significant in landslides of soft and loose materials.In this work, we provide a synthesis on the existing case histories showing f0 and dV/V reversible modifications,with the aim of analyzing the driving thermo-mechanical mechanisms. Eleven applications of long-term ambientseismic noise monitoring were collected for this purpose, including seven rock sites and four landslides indestructured or loose materials, reported in literature between 2012 and 2018. The majority of the sites are locatedin the Alpine context (France, Switzerland and Italy). Daily and seasonal f0 and dV/V fluctuations recordedin the different studies were quantified and summarized. The relation of these variations with temperature andwater was then further investigated. In particular, both in-phase and out-of-phase relationships between seismicparameters and temperature were highlighted, with different time of response (delay) of f0 and dV/V to themeteorological changes. Several driving mechanisms were found to generate this variety of responses to theexternal modifications, including temperature control on fracture opening/closing, stress conditions and bulkrigidity within the rock mass or modification in the mechanical properties of clayey materials. Water seepagewas found to be dominant in other sites, while the combined effect of temperature and water, leading to iceformation, significantly affected both f0 and dV/V values during freezing periods. The recognized driving forceswere observed to either strengthen each other or generate opposite effects on the recorded seismic parameters.Eventually, the obtained results were critically analyzed to compare f0 and dV/V performances in tracking thereversible changes in the different scenarios and to propose new research perspectives for removing or even usingthese changes towards a better understanding of the site stability.

Seismic noise parameters as indicators of reversible modifications in slope stability: a review

https://iris.polito.it/retrieve/handle/11583/2746472/264320/EGU2019-2095.pdf

Seismic noise parameters as indicators of reversible modifications in slope stability: a review

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